A robber brandishing two .357 magnums yesterday corralled 20 employes of the Evans Farm Inn in Mclean -- including the general manager, executive chef, dishwashers and a salesman with bad timing -- and locked them in a tiny mesh cage in the kitchen while he scoured the restaurant for money.

Ralph Evans, owner of the rambling Colonial-style restaurant, knew his workers were exhausted from serving 3,000 Easter meals, and, when he could get none of them on the telephone, he initially thought some of them might have slept late.

But after calling the restaurant more than 20 times and finding no answer, Evans dispatched a busboy to see what was wrong.

What the busboy found was the employes locked in a tiny kitchen service bar. Five were in handcuffs.

And none was sure whether the robber wearing a black coat and green baseball cap -- who had accosted each of them as they arrived, demanded money and locked them in the service bar for almost two hours -- was still in the building.

Fairfax County police said the robber broke into the restaurant about 8 a.m. He was still at large late yesterday after police dogs and a helicopter searched the restaurant and the surrounding area in vain.

The robber finally forced the restaurant's general manager to open an office safe and seized a "substantial" amount of money, police said. Evans said the amount taken was less than $2,000.

The robber may not have banked on the modern penchant for plastic, Evans suggested. "I guess [the robber] was not aware that most people dining out in restaurants today use credit cards," he said. "He expected to see piles of money."

In addition to the employes, the robber also locked up a linen service worker who had come to retrieve dirty tablecloths and a salesman who just wanted to see the manager.

As each person arrived, "[the robber] just approached them one after the other. He kept trying to get money," said Fairfax County police spokeswoman Connie Curran.

Executive Chef Inan Sarsour, who is called Chef Eddie, was walking in the back door about 8:10 when a man put a gun to his back and said, "This is a holdup. You do what I say and you won't get hurt. Do what I say and you'll live to see Easter again."

Sarsour said the robber led him through the kitchen to the service bar, a small area with steel mesh walls, shelves of liquor bottles and jars of sliced limes. Five employes were already there, Sarsour said -- four handcuffed together in pairs and one with his hands cuffed behind him.

As customers trickled in for dinner yesterday, Evans assessed the damage -- one broken window, the stolen cash and two telephones the robber had torn from the walls. It was the first robbery since the restaurant opened in 1957, he said, and added, "I hope it's the last."

"[The robber] seemed to have thought it out," Evans said. "Easter is one of our busy days. He was looking for a whole bunch of money, and he must have been annoyed that he didn't find any."